The CMakeCommands.build_command test performs output/error checking
so move it over to RunCMake to re-use the generalized infrastrucure.
This is the only test left using Tests/CMakeCommands/CMakeLists.txt
so remove it.
The CMakeOnly directory added by commit 9a20abf0 (Add infrastructure for
CMake-only tests, 2012-01-11) was sufficient only for tests that always
run CMake to successfully configure a project. Later commit eeaaffcb
(find_package: Test error and warning messages in failure cases,
2012-02-28) added a sample test that covers failure cases.
Generalize the above to create new "RunCMake" test infrastructure that
can run CMake multiple times for a single project with different
variations and check for expected result/stdout/stderr. Allow for both
successful and failing CMake project configuration cases. This will be
useful to test error messages and failure behavior.
Brad King